NIDA science-based guidelines recommend comprehensive, community-driven interventions to prevent HIV among IDUs. This study uses a new rapid policy assessment and response (RPAR) process to respond to legal structural barriers to HIV prevention among injection drug users (IDUs) in Central and Eastern Europe. The RPAR builds on the World Health Organization's rapid assessment and response process, by integrating into it legal and policy research with a focus on the implementation of law and policy as factors structuring the health risks of IDUs. The proposal also includes a cross-national study of the implementation of the RPAR in Ukraine, Poland and Russia in order to examine how structural barriers operate under a variety of contrasting conditions - epidemic, economic, and political/legal. The specific aims of the project are: 1) to use the RPAR to document laws and law enforcement practices in the three countries; 2) to build the capacity of local lawyers, social science researchers and public health personnel to collect and use data on laws, policies, and practices to foster solutions to community health problems; 3) to evaluate the RPAR as a means of collecting data and training local researchers; and 4) to disseminate the research results. The planned research will achieve these aims by using RPAR to: collect existing legal, criminal justice and epidemiological data; develop a community advisory board and process; conduct focus groups (N=90 individuals); identify and interview key informants (N=120); summarize and analyze the quantitative and qualitative data produced; prioritize policy and practice responses with the community advisory board; and disseminate the results. Implementation of the RPAR will be evaluated using process measures to measure: 1) local research and production of the research product; 2) local community engagement in policy and practice change; and 3) progress towards changes in policies or law enforcement practices with the potential to slow the epidemic. The larger three-country analysis will use qualitative methods to conduct a comparative analysis to identify ways in which law and legal practices are structural mediators of and influence regional HIV risks and community intervention capacity.